Thin film heat transfer gauges have been instrumented onto flexible plastic substrates which can be adhesively bonded to plastic or metal models. These new gauges employ standard analysis techniques to yield the heat flux to the model surface and have significant advantages over gauges fired onto machinable glass or those used with metal models coated with enamel. The main advantage is that the construction of the gauges is predictable and uniform, and thus calibration for thickness and geometric properties is not required.
The new gauges have been used to measure the heat transfer to an annular turbine nozzle guide vane in the Oxford University Cold Heat Transfer Tunnel. Engine-representative Mach and Reynolds numbers were employed and the free-stream turbulence intensity at NGV inlet was 13%.
The vanes were either precooled or preheated to create a range of different thermal boundary conditions. The gauges were mounted on both perspex and aluminium NGVs and the heat transfer coefficient was obtained from the surface temperature history using either a single layer analysis (for perspex) or double layer (for aluminium) analysis. The surface temperature and heat transfer levels were also measured using rough and polished liquid crystals under similar conditions. The measurements have been compared with computational predictions.
Lamikanra et al.T Regulatory Cell Migration and Vitamin D association with vitamin D status. Important for cellular therapies requiring isolation of Tregs, the absolute number of β7 + CD4 + CD25 + FOXP3 + Tregs was positively associated with 25(OH)vitamin D3 (R 2 = 0.0208, r = 0.184, p = 0.021) whereas the absolute numbers of CLA + CD4 + CD25 + FOXP3 + Tregs in the periphery were not influenced by vitamin D status. These baseline observations provide new opportunities to utilize seasonal variables that influence Treg numbers and their migratory potential in patients or donors.
Aerodynamic and heat transfer measurements have been made on the hub and casing endwalls of an annular cascade of high pressure nozzle guide vanes. The measurements have been made over a range of engine representative Mach and Reynolds numbers and with large levels of freestream turbulence intensity.
The transient liquid crystal technique has been employed, which has the advantage of yielding full surface maps of heat transfer coefficient. Computational predictions and aerodynamic measurements of Mach number distributions on the endwall surfaces are also presented, along with surface-shear flow visualisation using oil and dye techniques. The heat transfer results are discussed and interpreted in terms of the secondary flow and Mach number patterns.
Scurvy was at one time one of the most wide‐spread diseases, especially among seamen on long voyages. Little was known about the causes or treatment of the disease, but in 1753 James Lind showed that it could be prevented and cured by eating fresh fruits and vegetables. Captain Cook in his voyages made full use of this discovery to keep his crew in good health. In 1842, Budd suggested that scurvy was the result of ‘abstinence from vegetables and fruits’, but it was not until 1907 that this was demonstrated in practice, when Hoist and Frölich produced experimental scurvy in guinea pigs by using a restricted diet. In 1932 the active factor, ascorbic acid, was isolated in a pure form from lemons by Zilva and found to be identical with a compound obtained by Szent‐Györgyi from cabbages and adrenal glands in 1928. Finally, Haworth and Hirst identified the structure of ascorbic acid or vitamin C, which was synthesised in the same year by Reichstein and others.
Aim
NICE guidance recommends patients with renal colic be offered surgical treatment, including extracorporeal shockwave lithotripsy (ESWL), within 48 hours if pain is uncontrolled or stones unlikely to pass. We compared outcomes for ureteric stone passage after ESWL with those of observation to ascertain the relative benefits of ESWL.
Method
We collected data on stone location, size, and number of ESWL treatments required prospectively over 18 months. Stone passage was confirmed radiologically. Data were compared with MIMIC, a multi-centre collaborative study examining spontaneous stone passage after observation alone.
Results
166 patients had ESWL for ureteric stones. Median size was 6.5mm (IQR 5.0-8.0mm). 57.2% (N = 95) were proximal stones. Smaller stones required fewer treatments (P = 0.003). Patients with a ureteric stone <5mm required median 1.0 ESWL treatments (IQR 1.0-2.0). Ureteric stones 5-7mm had median 1.0 treatments (IQR 1.0-2.0) and stones >7mm median 2.0 treatments (IQR 1.0-2.0). Compared to MIMIC, patients with ESWL for stones <5mm were 11% more likely to achieve stone clearance (100.0% vs 89.0%, P = 0.001). ESWL for 5-7mm stones had 28.1% greater clearance compared to observation (77.1% vs. 49.0%, P < 0.001) and ESWL for stones >7mm 21% greater likelihood of clearance (50.0% vs. 29.0%, P < 0.001). Proximal ureteric stones were 16.4% more likely to pass with ESWL than observation (68.4% vs 52%, P = 0.02). Distal stones showed similar passage with ESWL (77.5%) and observation (83.0%), P = 0.43.
Conclusions
Proximal ureteric stones and those >5mm stones benefit most from ESWL. Results aid identification of patients whose stones are less likely to pass and warrant urgent review to consider ESWL.
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